Abstract: The explosion in the use of social media resources across society has extended to medicine, and perhaps nowhere is it more prevalent than in the field of infectious diseases. Physicians are using blogs to write about infectious diseases, new therapies, and their experiences with them. “Infoepidemiology” promises to quickly uncover future outbreaks without the need to cross oceans or to don a respirator. Infectious disease clinicians are sharing ideas, promoting organizational and philanthropic awareness, and professionally interacting on social networks such as Facebook. YouTube and other media sharing sites have become new resources for remote medical learning and educational collaboration. At the same time, personal and professional users of social media must confront challenging issues such as professionalism, medical confidentiality, peer review, and privacy concerns.